Group 7

Question 1

how to test for halide ions

Answer 1

nitric acid and add silver nitrate

Question 2

what are the positive results of testing for halide ions

Answer 2

AgCl - white
AgBr - cream
AgI - yellow

Question 3

how to determine what halide ion is present as a compound with Ag in an unknown solution

Answer 3

AgCl = dissolves in dilute ammonia
AgBr = dissolves in conc. ammonia
AgI = does not dissolve

Question 4

What type of agents are halide ions?

Answer 4

reducing

Question 5

What type of agents are halogens?

Answer 5

oxidising

Question 6

What are the weakest reducing agents?

Answer 6

F + Cl

Question 7

What is the acid-base reaction of F to produce a hydrogen halide?

Answer 7

NaF(s) + H2SO4(l) -> NaHSO4(s) + HF(g)

Question 8

What is the acid-base reaction of Cl to produce a hydrogen halide?

Answer 8

NaCl(s) + H2SO4(l) -> NaHSO4(s) + HCl(g)

Question 9

What is the strongest reducing agent?

Answer 9

I-

Question 10

What is the acid-base reaction of Br to produce a hydrogen halide?

Answer 10

NaBr(s) + H2SO4(l) -> NaHSO4(s) + HBr(g)

Question 11

What is observed when Florine and Chlorine produce hydrogen halides?

Answer 11

steamy white fumes

Question 12

What is observed when bromine produces a hydrogen halide?

Answer 12

orange fumes

Question 13

What is the redox reaction of the Br- to Br2 in the acid base reaction?

Answer 13

2H+ + 2Br- + H2SO4 ->Br2 + SO2 + 2H2O

Question 14

What is the overall equation of Br2 reacting with sulfuric acid?

Answer 14

2NaBr(s) + 3H2SO4(l) -> 2NaHSO4(s) + SO2(g) +2H2O(g)

Question 15

What is the acid-base reaction of I to produce a hydrogen halide?

Answer 15

NaI(s) + H2SO4(l) -> NaHSO4(s) + HI(g)

Question 16

What is the redox reaction of the I- to I2 and produces SO2 in the acid-base reaction?

Answer 16

2H+ + 2I- + H2SO4 ->I2 + SO2 + 2H2O

Question 17

What is the observation of the acid-base reaction of I?

Answer 17

white misty fumes

Question 18

What is the observation of the redox reaction reaction of I- to I2(s)?

Answer 18

black solid

Question 19

What is the observation of the redox reaction reaction of I- to I2(g)?

Answer 19

purple fumes

Question 20

What is the redox reaction of the I- to I2 and produces S(s) in the acid-base reaction?

Answer 20

6H+ + 6I- + H2SO4 -> 3I2 + S + 4H2O

Question 21

What is the redox reaction of the I- to I2 and produces H2S in the acid-base reaction?

Answer 21

8H+ + 8I- + H2SO4 -> 4I2 + H2S + 4H2O

Question 22

What observation can be made when S is formed?

Answer 22

yellow ppt

Question 23

What observation can be made when H2S is formed?

Answer 23

gas with bad egg smell

Question 24

What is a disproportionation reaction?

Answer 24

where an element oxidises and reduces in the same reaction

Question 25

What is the reaction of Chlorine and water?

Answer 25

Cl2(g) + H2O(l) -> HClO(aq) + HCl(aq)

Question 26

What is the reaction of Chlorine and water with sunlight?

Answer 26

Cl2(g) + H2O(l) -> 4H+ +4Cl- + O2

Question 27

How is bleach made?

Answer 27

Cl2(aq) + 2NaOH(aq) -> NaCl(aq) + NaClO(aq) + H2O(l)

Question 28

What observation can be made when bleach is made?

Answer 28

green -> colourless